Concerns have once again been raised about using the private sector to provide care to NHS patients - a policy championed by the Labour government.

A report by the Commons Health Committee, published on Wednesday accepts that using the private sector to provide extra capacity is necessary in the short-term.

But it warns the NHS must have sufficient capacity itself, and must not be in the position where it could be held to ransom by the private sector in the future.

So why did the NHS look to the private sector for services in the first place?

The NHS must have its own acute capacity so that, in the future, we don't have to rely on the private sector in the way we do currently

David Hinchliffe, Health Committee chairman

In fact, using the private sector to provide NHS care is nothing new.

It has taken place on an informal basis for many years and the Concordat, the agreement between the government and the private sector signed in November 2000, simply formalised that.

But, according to Anthony Harrison, researcher for independent think-tank the King's Fund, the reason the government went to the private sector then was "panic".

He said five months earlier, the government had published its 10 year plan for the NHS.

Pragmatism

Mr Harrison said: "They realised, when they set out their plan for what was needed, that they had to get hold of every resource possible."

The Labour government was criticised for what was seen as a shift in ideology, but Mr Harrison said it was simply "pragmatism".

But some disagree. Simon Burns, Conservative MP for Chelmsford West and a member of the Health Committee, said: "If five years ago, we had published the report saying this is where we would be after five years of a Labour government, you would say we were living in cloud-cuckoo land.

"Obviously the government has done this to get themselves out of a huge hole because they could not keep to their promises on waiting lists."

But now the private sector is involved, concerns have been raised about its impact on the NHS in the future.

The arguments centre on the best use of the finite pool of resources available for NHS patient care; whether that be staff, buildings or funding.

The Health Committee report raised concerns about the impact of the Concordat on NHS staff resources, as consultants can work in both public and private sectors, and more use of the latter will reduce their availability for the former.

And because there is an uneven distribution of private sector capacity, the MPs said it was important decisions could be made locally about where funds should best be targeted to benefit NHS patients, so resources could be used to buy private care or improve NHS services.

Dr Peter Hawker, chairman of the British Medical Association's consultants' committee said there should be a rigorous examination of whether the private sector offered value for money.

He added: "The relationship between a consultant's NHS and private work is being addressed in the current negotiations for a new contract for consultants.

"We are working towards a contract that would clarify the consultant's different roles and ensure that a perceived conflict of interest does not occur."

PFI concerns

The huge private finance initiative hospital building scheme - where the private sector builds hospitals and rents them back to the NHS - has attracted particular concern.

Critics such as the union Unison have expressed concerns about the costs to the health service of such schemes - and whether they are value for money.

These costs escalate, they say, and those extra bills squeeze funds from other parts of the health service.

Anthony Harrison agrees the NHS has suffered, and could do so in the future - most likely in community services: "It's correct to suggest that other services have been squeezed in order to pay for the new hospitals."

Unison also suggests bed numbers have fallen significantly in PFI schemes, but Mr Harrison says the schemes themselves were not to blame.

Flexibility

There is agreement that, for the future, the NHS needs to be self-sufficient in terms of providing hospital care.

If it is not, the fear is that the private sector would be able to name its price for services the NHS wanted to buy.

MPs and NHS experts also warn that money should not ploughed into private sector services when it should be put to better use improving public sector services.

David Hinchliffe, chairman of the committee said: "It's important that the NHS itself develops.

"The NHS must have its own acute capacity so that, in the future, we don't have to rely on the private sector in the way we do currently."

In the future, Mr Harrison predicted, the health service would continue to make use of the private sector - but it would make up a tiny proportion of the total care provided by the NHS.

"I think things will continue in the same way, with the private sector having a gradually incremental role.

"There would have to be quite a cataclysmic event to make a big shift."

He added that if there was to be a huge shift, market controls would be needed to ensure that the NHS was not asked to pay astronomical prices for private sector healthcare.

But he thought that situation was unlikely to happen.

"If you built up use of the private sector enormously, the public sector would be vulnerable. But there's no chance of that at the moment."